Highest temperature in Seoul (Incheon) on August 15?

Platform comparison

Market context

The market is pricing zero probability that Seoul's highest temperature on 15 August 2026 will exceed the upper threshold of its resolution range. This reflects the crowd's assessment that the peak daily temperature at Incheon International Airport will fall below whatever bracket the market has defined, though the specific temperature bands are not detailed in the available specification.

Seoul experiences peak summer heat in mid-August, with historical August averages around 29°C and daily highs frequently reaching 32–35°C under typical conditions. Extreme heat events pushing above 38°C have occurred in recent years—notably the 2018 heatwave and isolated days in 2022—but these remain outliers rather than the norm. The 0% implied probability suggests the market has anchored to a threshold well above Seoul's typical August range, or traders are heavily discounting the likelihood of an exceptional weather event on that specific date. Historical precedent indicates that whilst extreme temperatures are possible, they require specific atmospheric conditions (heat domes, stalled high-pressure systems) that cannot be reliably predicted two years in advance.

Traders monitoring this market should track seasonal climate forecasts released by the Korea Meteorological Administration in the months preceding August 2026, which typically provide guidance on whether the summer will trend warmer or cooler than normal. El Niño or La Niña patterns, which influence East Asian summer temperatures, will be relevant indicators. The resolution methodology's reliance on Weather Underground's Daily Observations table rather than summary figures introduces a minor technical dependency; any discrepancies between reporting sources could affect settlement, though Incheon's airport station is a standard WMO observation point with consistent historical records.

Methodology

Methodologically we separate two layers: the live probability (Polymarket mid-price) and the platform attributes (fee, KYC, settlement currency, payment rails). That keeps the comparison honest — a single canonical probability across the row, with the venue-by-venue trade-offs spelt out in the columns next to it.

Resolution & payout

Settlement runs on-chain. Polymarket's contract logic separates YES and NO shares as conditional tokens; at resolution the winning share lifts to $1.00 and the losing one to $0. The outcome input comes from the UMA Optimistic Oracle, which secures against bad resolution with a bond + dispute window.

Once finalised, the smart contract pays USDC to the holders' wallets within minutes — no withdrawal fees beyond Polygon network gas. Kalshi settles in USD via CFTC clearance, Betfair in account currency net of commission, Manifold in play-money mana with no cash-out.

FAQ

How does resolution work?

Through the UMA Optimistic Oracle on Polygon: a proposer submits the outcome, a two-hour challenge window opens, and USDC payouts settle automatically once the result is final.

What's the difference between YES and NO shares?

A YES share pays $1.00 if the event happens, $0 otherwise. A NO share pays $1.00 if the event doesn't happen. The market price between 0¢ and 100¢ is the implied probability.

What does Polymarket cost to trade?

Polymarket itself charges 0% — the only cost is the Polygon network fee, typically under $0.01 per transaction. Off-chain venues like Kalshi or Betfair charge 2-7% commission.

How fast are USDC deposits?

Polygon credits deposits after 12 confirmations — usually under 30 seconds. Withdrawals follow the same path and land back in your wallet within minutes.

Do I need to KYC for this market?

On Polymarket directly, no — it's wallet-based. Intermediary brokers like Who Will Win 2026 trigger KYC only above $1,500 of lifetime trading volume; under that you trade pseudonymously with a single wallet address.